KR102338975B1 - Insulation coating laminated metal plate and metal substrate - Google Patents

Abstract

The insulating film-laminated metal plate of the present invention has a metal plate and an insulating film laminated on at least one side of the metal plate, wherein the insulating film contains a thermosetting resin, and the thermosetting resin includes a terephthalic acid-derived unit and an isophthalic acid-derived unit. A polyester resin comprising a dicarboxylic acid-derived unit containing 90 mol% or more in total and a polyol-derived unit containing 90 mol% or more of a polyol-derived unit having 2 to 5 carbon atoms, the above dicarboxylic acid-derived units The molar percentage of the terephthalic acid-derived unit is 40 to 70%, the molar percentage of the isophthalic acid-derived unit in the dicarboxylic acid-derived unit is 30 to 60%, and the adjusted average carbon number of the polyol-derived unit calculated by the following formula (1) is less than or equal to 3.4.

Description

Insulation coating laminated metal plate and metal substrate

The present invention relates to an insulating coating laminated metal plate and a metal substrate. More specifically, it relates to an insulating film-laminated metal plate and a metal substrate used in a top emission type organic EL device or a substrate type thin film solar cell.

Organic semiconductors are flexible and can be reduced in thickness, and since they are power-saving, applications to organic electronic devices such as top emission type organic EL (electroluminescence) elements and substrate type thin film solar cells are expected. The said organic EL element is equipped with the light emitting layer containing an organic semiconductor, for example, the anode which consists of ITO (indium tin oxide) which has transparency and electroconductivity, and the cathode which consists of IZO (indium zinc oxide), for example. is additionally provided. On the other hand, the said solar cell is provided with the photoelectric conversion layer which consists of an organic semiconductor, and is further equipped with the back electrode and surface electrode which consist of ITO, respectively, respectively.

When glass is used as a substrate for an organic electronic device, there is a problem that it is prone to cracking and lacks workability. On the other hand, when plastic is used, there is a problem that the provision of a gas barrier layer is necessary because it has moisture permeability. Therefore, as a board|substrate of an organic electronic device, employ|adoption of the insulating film laminated|multilayer metal plate which laminated|stacked the insulating film on the metal plate is examined.

For example, Patent Document 1 discloses an insulating film-laminated metal plate having a surface roughness of 30 nm or less and a film thickness of 10 to 40 µm, and in which only one film containing polyester as a thermosetting resin is laminated on the surface of the metal plate. In addition, Patent Document 2 is provided with one or more thermosetting resin coating layers on one or both surfaces of a metal plate, and the resin coating layer has a surface roughness of 20 nm or less and a total film thickness of 1 to 30 μm. An insulating coating laminated metal sheet in which the resin is a polyester resin is disclosed.

By laminating an anode, a light emitting layer and a cathode on the insulating film of the said insulating film laminated metal plate in this order, the said organic electroluminescent element is obtained. The light emitting layer emits light by providing this organic EL element in a light emitting circuit and allowing an electric current to flow.

On the other hand, the said solar cell is obtained by laminating|stacking a back surface electrode, a photoelectric conversion layer, and a surface electrode in this order on the insulating film of the said insulating-film-laminated metal plate. By installing this solar cell in a power generation circuit and irradiating sunlight, electric charge is moved in a photoelectric conversion layer, and the said solar cell generates electricity.

Japanese Patent Laid-Open No. 2014-208479 Japanese Patent Laid-Open No. 2016-193580

When the above-mentioned organic EL device is produced using the insulating film laminated metal plate disclosed in Patent Literature 1 and Patent Literature 2 and light is emitted, the organic EL device has a width of 5 to 10 μm and a length of 20 to 50 μm as shown in FIG. It has an arc shape and sometimes emits light. Compared with an organic EL element in which the light emitting layer surface emits light uniformly, the organic EL element exhibiting such an arcuate shape exhibits a lack of color unevenness and insufficient luminous intensity, and thus does not satisfy the required performance as an organic EL element. As will be described later, the arc-shaped light emission is caused by wrinkles generated on the surface of the conductive thin film layer when the conductive thin film layer is formed by sputtering on the insulating film of the insulating film-laminated metal plate.

On the other hand, when the solar cell is produced and generated using the insulating coating laminated metal plate disclosed in Patent Literature 1 and Patent Literature 2, the amount of power generation may decrease due to wrinkles generated on the surface of the conductive thin film layer.

Therefore, the metal substrate in which wrinkles do not generate|occur|produce on the surface of a conductive thin film layer, and the insulating-film laminated metal plate which the said wrinkles do not generate|occur|produce at the time of the conductive thin film layer formation by sputtering are calculated|required.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide an insulating film-laminated metal plate capable of suppressing the occurrence of wrinkles when forming a conductive thin film layer by sputtering, and a metal substrate in which the occurrence of wrinkles on the surface of the conductive thin film layer is suppressed. do it with

One aspect of the present invention has a metal plate and an insulating film laminated on at least one side of the metal plate, wherein the insulating film contains a thermosetting resin, and the thermosetting resin comprises a unit derived from terephthalic acid and a unit derived from isophthalic acid. It contains a polyester resin composed of a dicarboxylic acid-derived unit containing 90 mol% or more and a polyol-derived unit containing 90 mol% or more of a polyol-derived unit having 2 to 5 carbon atoms, the terephthalic acid derived from the dicarboxylic acid-derived unit The molar percentage of the unit is 40 to 70%, the molar percentage of the isophthalic acid-derived unit in the dicarboxylic acid-derived unit is 30 to 60%, and the adjusted average carbon number of the polyol-derived unit calculated by the following formula (1) is 3 It is an insulating film laminated metal plate for forming a conductive thin film layer on the said insulating film which is 4 or less.

[Equation 1]

Another aspect of the present invention is a metal substrate in which a conductive thin film layer is laminated on an insulating film of the insulating film-laminated metal plate.

The objective, characteristic, aspect, and advantage of this invention become clearer with the following detailed description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure substitution photograph which shows the optical microscope image of the light emission state in the surface of the top emission type organic electroluminescent element produced using the conventional insulating-film-laminated metal plate.
Fig. 2 shows the embodiment No. It is a figure substitute photograph which shows the atomic force microscope image of the surface of the ITO layer in the metal substrate of 1.
Fig. 3 shows the No. It is a figure substitute photograph which shows the atomic force microscopy image of the surface of the ITO layer in the metal substrate of No. 2.

First, the outline of the process leading to the present invention will be described by taking the case where an OLED element (organic light emitting diode element) which is a top emission type organic EL element is produced as an example.

When manufacturing an OLED device using an insulating film-laminated metal plate in which an insulating film is laminated on a metal plate, the insulating film-laminated metal plate is first washed, and an ITO layer serving as an anode is laminated on the insulating film by sputtering. Thereby, the metal substrate which has an ITO layer as a conductive thin film layer is obtained. Next, on the ITO layer, a hole injection/transport layer, a light emitting layer, and an electron transport layer are laminated in this order by vapor deposition or coating and heating the respective layer raw material compositions. Then, on the electron transport layer, the IZO layer which is a cathode is formed by sputtering. Then, a transparent encapsulation glass is laminated on the IZO layer. Thereby, an OLED element is obtained. Since all of the organic semiconductors constituting the hole injection/transport layer, the light emitting layer, and the electron transport layer have low charge mobility, the thickness of these layers is set to a value of several tens of nm to several hundreds of nm, respectively. In addition, the thickness of the IZO layer constituting the cathode is also set to a value ranging from several tens of nm to several hundreds of nm.

When the OLED element obtained in this way is made to light-emit, color nonuniformity and lack of light emission illuminance may arise. MEANS TO SOLVE THE PROBLEM The present inventors observed the light emission state of the surface of the OLED element in which color nonuniformity occurred with the optical microscope. The observation result is shown in FIG. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure substitution photograph which shows the optical microscope image of the light emission state in the surface of the OLED element in which the said color nonuniformity arose. As a result, it became clear that color nonuniformity had arisen when the OLED element showed the arc shape of 5-10 micrometers in width and 20-50 micrometers in length, and light-emitted. In addition, an OLED device that emits light while exhibiting such an arc shape has a lower luminous intensity as compared to an OLED device that emits light over the entire surface uniformly, and the lifetime as an OLED device is due to shortening of the lifespan of strongly emitting portions in the light emitting layer. It was also found that this relatively easy to shorten.

MEANS TO SOLVE THE PROBLEM The present inventors earnestly examined the cause in which the OLED element in which color nonuniformity produced shows the said arc shape of the said contrast. And, the cause is that, when the ITO layer is formed, wrinkles having a height difference from several tens nm to several hundred nm are generated on the surface of the ITO layer, and the wrinkles are formed in a thin hole injection/transport layer, a light emitting layer, an electron transport layer and It was found that this was because it was reflected even to the device surface by interposing the IZO layer.

The wrinkles on the surface of the ITO layer are affected by the heat of sputtering, and it is assumed that the insulation film located below the ITO layer is heated to about 200 to 250 ° C.

Then, various measures were investigated in which an insulating film does not soften under the temperature of about 200-250 degreeC even by sputtering at the time of ITO layer formation. And, by containing a polyester resin of a specific composition in the thermosetting resin contained in the insulating film, softening due to the temperature rise of the insulating film caused by sputtering is suppressed, and the occurrence of wrinkles in the ITO layer, which is a conductive thin film layer, is suppressed. The present invention was completed.

On the other hand, in the present specification, wrinkles are 20 to 50 μm in length, 5 to 10 μm in width, and 100 nm or more in height (difference between mountains and valleys) formed on the surface layer of the object to be observed. It refers to the irregularities visible when the surface is observed with an atomic force microscope. An example of a wrinkle is shown in FIG. Fig. 3 shows the No. It is a figure substitute photograph which shows the atomic force microscopy image of the surface of the ITO layer in the metal substrate of No. 2.

In addition, in this specification, the molar percentage of the terephthalic acid-derived unit occupied in the dicarboxylic acid-derived unit means the percentage of the molar part of the terephthalic acid-derived unit with respect to 100 molar part of dicarboxylic acid-derived units.

[Insulation film laminated metal plate]

Next, an insulating film laminated metal which is one aspect of the present invention will be described.

The insulating film-laminated metal plate of the present invention has a metal plate and an insulating film laminated on at least one surface side of the metal plate. The insulating film contains a thermosetting resin. The thermosetting resin is a dicarboxylic acid-derived unit containing 90 mol% or more in total of terephthalic acid-derived units and isophthalic acid-derived units, and polyol-derived units containing 90 mol% or more of polyol-derived units having 2 to 5 carbon atoms. It contains an ester resin. The molar percentage of the terephthalic acid-derived unit in the dicarboxylic acid-derived unit is 40 to 70%. The molar percentage of the isophthalic acid-derived unit in the dicarboxylic acid-derived unit is 30 to 60%. The adjusted average carbon number of the polyol-derived unit computed by said Formula (1) is 3.4 or less. The insulating film laminated metal plate of this invention is used in order to form a conductive thin film layer on the said insulating film.

Hereinafter, the reason prescribed in this way will be described.

1. metal plate

The metal sheet used for the insulating coating laminated metal sheet of the present invention is a cold rolled steel sheet, a hot-dip pure galvanized steel sheet, an alloyed hot-dip Zn-Fe-coated steel sheet, an alloyed hot-dip Zn-5%Al-coated steel sheet, a hot-dip 55% Al-Zn alloy coated steel sheet, and electric a pure galvanized steel sheet, an electrical Zn-Ni plated steel sheet, an aluminum sheet, or a titanium sheet. As the metal plate, an untreated material (so-called bare plate) to which the surface is not chemically treated can be used. However, from the viewpoint of improving the adhesion between the metal plate and the insulating film by chemical bonding, it is preferable to use, as the metal plate, a chromate material in which the surface is chromated, or a non-chromate material in which the surface is non-chromated. . It is more preferable to use a non-chromate material as the said metal plate from a viewpoint of environmental conservation. The thickness of the said metal plate is not specifically limited. Depending on the use of the insulating coating laminated metal sheet, it is, for example, about 0.3 to 2.0 mm.

2. Insulation film

In the present invention, the insulating film has electrical insulation properties. More specifically, in use of an organic electronic device fabricated using the insulating film-laminated metal plate of the present invention, the insulating film has electrical insulation properties in which current does not leak to the metal plate from the layer located immediately above it.

An insulating film is laminated|stacked on the single side|surface side or both surfaces side of a metal plate depending on the use of the insulating-film-laminated metal plate. An insulating film may be laminated|stacked directly on the metal plate, and may be laminated|stacked on the metal plate through another layer. By laminating the insulating film on the metal plate, electrical insulation between the metal plate and the layer laminated on the upper layer side of the insulating film (eg, conductive thin film layer) is ensured.

Although the thickness of an insulating film is not specifically limited, From a viewpoint of ensuring stably the electrical insulation of an insulating film, it is preferable that the thickness of an insulating film is 10 micrometers or more. On the other hand, when the thickness of the insulating film exceeds 50 µm, since the electrical insulation of the insulating film tends to be saturated, the thickness of the insulating film is preferably 50 µm or less.

The insulating film mainly contains a thermosetting resin.

In addition, in order to adjust the emission color of an organic electronic device produced using the insulating film laminated metal plate according to the use of the insulating film laminated metal plate, the insulating film is, as will be described later, for example, a white pigment such as titanium oxide; You may contain 1 type(s) or 2 or more types of pigments of various colors, such as black pigments, such as carbon black. When the insulating film contains the pigment, it is possible to reflect light of a specific wavelength from the insulating film to the surface side among the light transmitted from the surface side of the insulating film to the metal plate side. For example, when an OLED element is produced using the insulating film-laminated metal plate of the present invention and the OLED element is made to emit light, the light emitted from the light emitting layer toward the metal plate is the light of a wavelength corresponding to the pigment from the insulating film to the element surface side. can reflect.

2-1. thermosetting resin

In the present invention, the thermosetting resin is a dicarboxylic acid-derived unit containing 90 mol% or more of terephthalic acid-derived units and isophthalic acid-derived units in total, and a polyol-derived unit containing 90 mol% or more of C2-C5 polyol-derived units. As the polyester resin constituted, the molar percentage of the terephthalic acid-derived unit in the dicarboxylic acid-derived unit is 40 to 70%, and the molar percentage of the isophthalic acid-derived unit in the dicarboxylic acid-derived unit is 30 to 60%, The polyester resin whose adjusted average carbon number of the unit derived from the polyol computed by said Formula (1) is 3.4 or less is contained.

2-1-1. polyester resin

The polyester resin is a polymer material having a large number of ester bonds formed by a condensation reaction of dicarboxylic acid and polyol, and since the ester group constituting the ester bond consists only of carbon atoms and oxygen atoms, affinity with water is low. Therefore, when manufacturing an organic electronic device using the insulating coating laminated metal plate of the present invention, even if water that adversely affects the organic electronic device penetrates into the insulating film containing the polyester resin, it is removed by drying. easy. For example, when an organic electroluminescent element is produced as an organic electronic device using the insulating-coated laminated metal plate of this invention, generation|occurrence|production of the dark spot (non-light emitting area|region) resulting from penetration of water can be suppressed.

The said polyester resin WHEREIN: The total molar percentage of the terephthalic acid-derived unit and isophthalic acid-derived unit which occupies for the dicarboxylic acid-derived unit is 90 % or more. Terephthalic acid, which is a raw material for terephthalic acid-derived units, and isophthalic acid, which is a raw material for isophthalic acid-derived units, are aromatic dicarboxylic acids and have excellent thermal stability. And these are cheaper than other aromatic dicarboxylic acids. For this reason, by making the said total molar percentage into 90 % or more, heat resistance is ensured although it is relatively low cost, and generation|occurrence|production of wrinkles can be suppressed at the time of the conductive thin film layer formation by sputtering. From the viewpoint of suppressing the manufacturing cost, the total mole percentage is preferably 100%. The terephthalic acid-derived unit and the isophthalic acid-derived unit in the dicarboxylic acid-derived unit can be identified, for example, by nuclear magnetic resonance (NMR method).

In the polyester resin, the molar percentage of terephthalic acid-derived units in dicarboxylic acid-derived units is 40 to 70%. The terephthalic acid-derived unit represents a structure that linearly elongates the polyester resin, and is a structural unit that increases the hardness of the polyester resin by suppressing the rotation of the polyester resin itself (rotation as a polyester resin molecule), and furthermore, insulation It has an effect|action which raises the hardness of a film. From the viewpoint of securing the hardness of the insulating film, the molar percentage of the terephthalic acid-derived units in the dicarboxylic acid-derived units is set to 40% or more. Preferably it is 50% or more. On the other hand, when the molar percentage of the terephthalic acid-derived units in the dicarboxylic acid-derived units is too high, the insulating film becomes too hard, and the workability of the insulating film-laminated metal sheet decreases. Therefore, the molar percentage of the terephthalic acid-derived unit in the dicarboxylic acid-derived unit is set to 70% or less. Preferably it is 60% or less.

In the polyester resin, the molar percentage of the isophthalic acid-derived unit in the dicarboxylic acid-derived unit is 30 to 60%. The isophthalic acid-derived unit represents a structure that bends the polyester resin, facilitates rotation of the polyester resin itself (rotation as a polyester resin molecule) to lower the hardness of the polyester resin, and furthermore, insulation It has the action of softening the film. From the viewpoint of ensuring the softness of the insulating film, the molar percentage of the isophthalic acid-derived units in the dicarboxylic acid-derived units is set to 30% or more. Preferably it is 40% or more. On the other hand, when the molar percentage of the isophthalic acid-derived unit occupied in the dicarboxylic acid-derived unit is too high, the insulating film becomes too soft. Therefore, the molar percentage of the isophthalic acid-derived unit in the dicarboxylic acid-derived unit is set to 60% or less. Preferably it is 50% or less.

In the polyester resin, the molar percentage of the polyol-derived unit having 2 to 5 carbon atoms in the polyol-derived unit is 90% or more. The polyol-derived unit having more than 5 carbon atoms is a structural unit that lowers the hardness of the polyester resin, and when the molar percentage exceeds 10%, the insulating film does not satisfy the required hardness, and when the conductive thin film layer is formed by sputtering This is because wrinkles occur. From the viewpoint of stably securing the hardness of the polyester resin, the molar percentage of the polyol-derived unit having 2 to 5 carbon atoms in the polyol-derived unit is preferably 100%. The polyol-derived unit having 2 to 5 carbon atoms in the polyol-derived unit can be identified, for example, by nuclear magnetic resonance.

The said polyester resin is obtained by the condensation reaction of the dicarboxylic acid containing terephthalic acid and isophthalic acid, and the polyol containing a C2-C5 polyol. Therefore, the said dicarboxylic acid may contain dicarboxylic acids other than terephthalic acid and isophthalic acid. Examples of such dicarboxylic acids include α,β-unsaturated dibasic acids such as maleic acid, fumaric acid, and itaconic acid, orthophthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, hexahydroisophthalic acid, hexahydro Terephthalic acid, succinic acid, malonic acid, glutaric acid, adipic acid, sebacic acid, 1,10-decanedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 2,3-naphthalenedi and saturated dibasic acids other than terephthalic acid and isophthalic acid, such as carboxylic acid and 4,4'-biphenyldicarboxylic acid. Among them, it is preferable to use one or two or more of 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, and 2,3-naphthalenedicarboxylic acid having a molecular structure similar to that of terephthalic acid and isophthalic acid.

On the other hand, the polyol may contain a polyol having 2 to 5 carbon atoms as well as a polyol having 6 or more carbon atoms. As the polyol, for example, ethylene glycols such as ethylene glycol, diethylene glycol, and polyethylene glycol, propylene glycol such as propylene glycol, dipropylene glycol, and polypropylene glycol Lycol, 2-methyl-1,3-propanediol, 1,3-butanediol, adduct of bisphenol A with propylene oxide or ethylene oxide, glycerin, trimethylolpropane, 1,3-propane Paindiol, 1,2-cyclohexane glycol, 1,3-cyclohexane glycol, 1,4-cyclohexane glycol, paraxylene glycol, bicyclohexyl-4, 4'-diol, 2,6-decalin glycol, tris(2-hydroxyethyl) isocyanurate, etc. are mentioned. Each of the polyol having 2 to 5 carbon atoms and the polyol having 6 or more carbon atoms may be used alone, or may be used in combination of two or more types as appropriate.

The polyol is preferably a diol, and the polyol having 2 to 5 carbon atoms is preferably a diol having 2 to 5 carbon atoms. And, as for the said polyol, it is more preferable that it is only the said C2-C5 polyol. Examples of the diol having 2 carbon atoms include ethylene glycol. Examples of the diol having 3 carbon atoms include 1,2-propanediol and 1,3-propanediol. As the diol having 4 carbon atoms, for example, 2-methyl-1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol , and 2,3-butanediol. Examples of the diol having 5 carbon atoms include neopentyl glycol and 1,5-pentanediol.

The said polyester resin WHEREIN: The adjusted average carbon number of the polyol-derived unit computed by said Formula (1) is 3.4 or less. The adjusted average carbon number of the polyol-derived unit is an index capable of adjusting the hardness of the insulating film at a temperature of about 200 to 250°C, and the present inventors discovered it in the course of reaching the present invention. In the polyester resin, since the polyol-derived unit has a chain hydrocarbon as a skeleton, it has a property of softening the polyester resin compared to the dicarboxylic acid-derived unit. When the adjusted average carbon number of the polyol-derived unit exceeds 3.4, the proportion of chain hydrocarbons in the polyester resin increases. As a result, the insulating film becomes soft at a temperature of about 200 to 250 ° C. Occurs. Wrinkle generation at the time of the conductive thin film layer formation by sputtering is suppressed, so that the adjusted average carbon number of a polyol-derived unit is small. It is preferable that it is 3.2 or less, and, as for the adjusted average carbon number of a polyol-derived unit, it is more preferable that it is 3.0 or less. However, since methanediol, which is a polyol having 1 carbon number, is unstable, the practical lower limit of the adjusted average carbon number of the polyol-derived unit is 2.0.

The average number of carbon atoms of the polyol-derived units in the formula (1) means the total of the values obtained by multiplying the number of carbon atoms in the individual polyol-derived units constituting the polyol-derived unit by the molar ratio of the individual polyol-derived units. For example, when the polyol-derived unit A is constituted by an individual polyol-derived unit A1 having a molar percentage X1 mol% of carbon number N1 and an individual polyol-derived unit A2 having a carbon number N2 molar percentage X2 mol%, the polyol-derived unit A The average number of carbon atoms N of is calculated as (N1×X1+N2×X2)/100. In addition, the number of carbon atoms of an individual polyol-derived unit refers to the total number of carbons contained in an individual polyol-derived unit, and is the sum of the carbon number of the main chain and the number of carbon atoms of the side chain of the individual polyol-derived unit.

2-methyl-1,3-propanediol and 1,4-butanediol are polyols having the same total carbon number of 4, but different from 3 and 4 carbon atoms in the main chain. It was confirmed by the experiments of the present inventors that in the insulating coating laminated metal sheet produced using the polyol containing each of these polyols individually, the wrinkles generated at the time of forming the conductive thin film layer were to the same degree.

2-1-2. crosslinking agent

In the present invention, the thermosetting resin contains a crosslinking agent. Thereby, the insulating film not only exhibits thermosetting property, but also improves heat resistance. And when an organic electronic device is produced using the insulating-film-laminated metal plate of this invention, deformation|transformation and quality change of an insulating film can be suppressed.

The crosslinking agent is not particularly limited as long as it is a substance capable of crosslinking the polyester resin, but a material having good compatibility with the polyester resin and good liquid stability is preferable. As such a crosslinking agent, various commercial items can be used suitably. For example, in the isocyanate system, Milionate (registered trademark) N, Coronate (registered trademark) T, Coronate (registered trademark) HL, Coronate (registered trademark) 2030, Suprasec (registered trademark) 3340, Dultsec 1350, Dultsec 2170, Dultsec 2280 (above, manufactured by Nippon Polyurethane Industries, Ltd.) In the melamine system, Nikalac (registered trademark) MS-11, Nikalac (registered trademark) MS21 (above, Co., Ltd.) Sanwa Chemical), Super Becamine (registered trademark) L-105-60, Super Becamine (registered trademark) J-820-60 (above, manufactured by DIC Corporation), in the epoxy system, Hardener HY951, Hardener HY957 (above, BASF product), Sumicure DTA, Sumicure TTA (above, Sumitomo Chemical Co., Ltd. make) etc. are mentioned.

Although the content rate in particular of the said polyester resin and the said crosslinking agent in a thermosetting resin is not restrict|limited, respectively, It is preferable that the content rate of a polyester resin is 50 mass % or more.

2-2. pigment

As the white pigment, for example, inorganic pigments such as titanium oxide, calcium carbonate, zinc oxide, barium sulfate, lithopone, and white lead, and organic pigments such as polyethylene, polystyrene, polyacrylate, urea resin, and melamine resin Pigments may be used. Among these, it is preferable to use titanium oxide exhibiting pure white color. When the insulating film contains the white pigment, the luminance of the organic EL element produced using the insulating film-laminated metal sheet of the present invention is improved.

As the black pigment, for example, black: organic pigments such as aniline black and nigrosine, and inorganic pigments such as carbon black and iron black can be used. When the insulating film contains the black pigment, the darkness at the time of non-light emission of the organic EL element produced using the insulating film-laminated metal plate of the present invention is improved.

As a red pigment, organic pigments, such as an insoluble azo system (naphthol system and anilide system) or a soluble azo system, For example, inorganic pigments, such as bengala, cadmium red, and a rostrum, can be used, for example. Examples of the yellow pigment include organic pigments such as insoluble azo (naphthol and anilide), soluble azo and quinacridone pigments and, for example, chromium yellow, cadmium yellow, nickel titanium yellow, yellow gold, strontium. Inorganic pigments, such as a chromate, can be used. As the green pigment, for example, an organic phthalocyanine pigment can be used. As a blue pigment, inorganic pigments, such as an organic phthalocyanine type pigment, a dioxazine type pigment, royal blue, ultramarine blue, cobalt blue, and emerald green, can be used, for example. As an orange pigment, organic pigments, such as a benzimidazolone type and a pyrazolone type, can be used, for example.

2-3. Surface roughness of insulating film

In the present invention, the preferred thickness of the insulating film is 10 to 50 µm. On the other hand, when producing an organic electronic device using the insulating-film-laminated metal plate of this invention, the preferable thickness of the conductive thin film layer formed on the insulating film is 0.01-1 micrometer so that it may mention later. As described above, since the thicknesses of the two differ greatly, the conductive thin film layer with a small thickness is influenced by the large insulating film with a large thickness, and quality defects are likely to occur. For example, when defects, such as pinholes, exist on the surface of an insulating film, it will become easy to penetrate|infiltrate water, and it will become easy to appear dark spots. In addition, when the insulating film has surface irregularities, the thickness of the conductive thin film layer formed on the convex portion of the insulating film is likely to be different from the thickness of the conductive thin film layer formed on the concave portion of the insulating film, which affects the quality and lifespan of the organic electronic device. easier to influence From the viewpoint of avoiding such a problem, the surface roughness in the 3 mm square region of the insulating film is preferably 10 nm or less, more preferably 5 nm or less, and still more preferably 3 nm or less. Thereby, it is also possible to suppress the wave ripples of the insulating film.

The surface roughness in a 3 mm square area can be measured by the measuring method mentioned later.

As a method of making the surface roughness in a 3 mm square region of the insulating film 10 nm or less, performing chemical mechanical polishing (CMP) on the surface of the insulating film is exemplified. Thereby, the insulating film surface can be made smooth.

The chemical mechanical polishing method is not particularly limited, and a known polishing method that is polished by the surface chemical action of the abrasive itself or the action of the chemical component contained in the polishing liquid may be used. The abrasive is also not specifically limited, For example, silica, alumina, ceria, titania, zirconia, germania, etc. can be used.

[Method for Producing Insulation Coated Laminated Metal Sheet]

Next, the manufacturing method of the said insulating-coated laminated metal plate is demonstrated.

It is preferable to laminate|stack an insulating film by the application method of apply|coating the composition for insulating film preparation on the surface of a metal plate or another layer. Therefore, it is preferable that the composition for insulating film preparation is liquid and also contains a solvent. There is no restriction|limiting in particular as long as the solvent used for the composition for insulation film preparation can melt|dissolve or disperse|distribute each component which the composition for insulation film preparation should contain. As a solvent, For example, Alcohol, such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, ethylene glycol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; aromatic hydrocarbons such as toluene, benzene, xylene, Solveso (registered trademark) 100 (manufactured by ExxonMobil), and Solveso (registered trademark) 150 (manufactured by ExxonMobil); aliphatic hydrocarbons such as hexane, heptane, and octane; esters such as ethyl acetate and butyl acetate; and the like. The composition for insulating film preparation can adjust solid content using the said solvent, for example.

The coating method in particular of the composition for insulation film preparation is not restrict|limited, A well-known method is employable suitably. As a coating method, the precoat method by the bar coater method, the roll coater method, the curtain flow coater method, the spray method, the spray Ringer method, etc. is mentioned, for example. Among these, the bar coater method, the roll coater method, the spray method, and the spray Ringer method are preferable from a viewpoint of cost etc. When using for a precoating method, for example, 190 degreeC or more and 250 degrees C or less are preferable, and, as for baking temperature, 200 degreeC or more and 240 degrees C or less are more preferable, for example. The drying temperature should just be a grade in which an insulating film does not deteriorate with heat|fever, for example, about 190-250 degreeC is preferable, and its 200-240 degreeC grade is more preferable. As the baking temperature and the drying temperature, a peak metal temperature (PMT) may be used.

The polyester resin and the manufacturing method of the insulating film laminated metal plate are as follows, for example.

A composition for forming a polyester resin containing a dicarboxylic acid containing 90 mol% or more of terephthalic acid and isophthalic acid in total, and a polyol containing 90 mol% or more of a polyol having 2 to 5 carbon atoms in a molar ratio of 1:1.5-2 as a catalyst Antimony trioxide is added, and the condensation reaction proceeds by heating at 180 to 210° C. for 180 minutes under atmospheric pressure. Then, while raising a temperature to 250 degreeC and reducing a pressure to 1-5 mmHg, while further advancing a condensation reaction for 180 minutes, the water produced by a condensation reaction is removed. Thereby, a polyester resin is obtained. Since the polyol is volatilized in the condensation reaction accompanying the removal of water in the latter half, the dicarboxylic acid-derived unit and the polyol-derived unit in the obtained polyester resin are about 1:1 in molar ratio. The exact amount of dicarboxylic acid and polyol to be added is determined based on the molar ratio of the dicarboxylic acid-derived unit and the polyol-derived unit in the polyester resin obtained from the composition for forming a polyester resin in which the content ratio of the dicarboxylic acid and the polyol is changed.

The obtained polyester resin, a crosslinking agent, and the pigment etc. which are added as needed are melt|dissolved in a solvent, and the solution (composition for insulating film preparation) obtained by dispersing is apply|coated to a metal plate, and it is heated. Thereby, an insulating film is formed on the metal plate, and the insulating film laminated|multilayer metal plate is obtained. Preparation of the said solution WHEREIN: It is preferable that content of solid content (a polyester resin, a crosslinking agent, a pigment, etc.) is 20-70 mass %. When content of solid content is less than 20 mass %, the viscosity of a solution becomes low too much, and it becomes necessary to repeat application|coating several times until it reaches the target thickness of an insulating film. On the other hand, when content of solid content exceeds 70 mass %, the viscosity of a solution will become high too much, and application|coating itself will become difficult. Moreover, it is preferable that the pigment ratio in solid content is 60 mass % or less. When the ratio of the pigment in solid content exceeds 60 mass %, the viscosity of a solution will become high too much, and application|coating itself will become difficult.

[Metal substrate]

Next, a metal substrate, which is another aspect of the present invention, will be described.

In the metal substrate of the present invention, a conductive thin film layer is laminated on the insulating film of the insulating film-laminated metal plate.

In the present invention, the conductive thin film layer is made of, for example, ZnO, ITO, or SnO ₂ to which Al, B, Ga, Sb, or the like is added. Usually, it is constituted by the ITO.

A single layer structure may be sufficient as the layer structure of a conductive thin film layer, and the laminated structure of two or more layers may be sufficient as it. Substances constituting each layer (ie, ZnO, ITO, or SnO ₂ ) may be the same or different.

Although the thickness in particular of a conductive thin film layer is not restrict|limited, 0.01-1 micrometer is preferable.

It is preferable that it is 100 nm or less, and, as for the surface roughness in the 3 mm square area|region of a conductive thin film layer, it is more preferable that it is 20 nm or less, It is still more preferable that it is 10 nm or less, It is still more preferable that it is 5 nm or less. Thereby, a solar cell with high power generation efficiency and an organic EL element with high light emission illuminance can be produced. The surface roughness in a 3 mm square area can be measured by the measuring method mentioned later.

Since the conductive thin film layer has heat resistance of about 200° C. or higher, an organic electronic device can be manufactured using the metal substrate of the present invention.

In the organic EL element produced using the metal substrate of the present invention, the conductive thin film layer functions as an anode. And since the conductive thin film layer has transparency, the light emitted by the light emitting layer to the metal plate side is reflected by the insulating film containing the pigment located below the conductive thin film layer.

[Method for Manufacturing Metal Substrate]

Next, the manufacturing method of the said metal substrate is demonstrated.

The conductive thin film layer is formed by sputtering. More specifically, while the insulating coating laminated metal plate of this invention is mounted in a vacuum container, the metal or metal oxide to be provided as a thin film is installed as a target. For example, when forming an ITO layer as a conductive thin film layer, the target which consists of ITO is used. Then, for example, a noble gas element such as argon or nitrogen is ionized by applying a high voltage to collide with the target. As a result, atoms or the like on the surface of the target are repelled and fly to reach the insulating film laminated metal plate, and a conductive thin film layer is formed on the insulating film.

[Substraight thin film solar cell]

Next, the substrate type thin film solar cell provided with the insulating film laminated metal plate of this invention is demonstrated.

The substrate solar cell may have any known structure as long as it has the insulating coating laminated metal plate of the present invention. It has a structure in which a photoelectric conversion layer and a surface electrode are laminated in this order. The photoelectric conversion layer is a layer that generates a current by absorbing the light that has passed through the transparent surface electrode, and the back electrode and the surface electrode are both for taking out the current generated in the photoelectric conversion layer, and both are made of a conductive material. . The surface electrode on the light-incident side needs to have light-transmitting properties. About the back electrode, the photoelectric conversion layer, and a surface electrode, the material similar to a well-known substrate type thin film solar cell can be used.

In the substrate solar cell, since sunlight is incident from the transparent surface electrode side, transparency of the insulating coating laminated metal plate is not required.

[Top emission type organic EL element]

Next, the top emission type organic electroluminescent element provided with the insulating-film laminated metal plate of this invention is demonstrated.

The top emission type organic EL device may have any known structure as long as it is provided with the insulating coating laminated metal plate of the present invention. The light emitting layer and the cathode are stacked in this order. For the anode, the light emitting layer, and the cathode, the same material as that of a known top emission organic EL device can be used.

In a top emission type organic EL device, since light is extracted through the cathode (without passing through the insulating film laminated metal plate), a non-transparent metal plate can be used as the substrate.

As described above, one aspect of the present invention has a metal plate and an insulating film laminated on at least one side of the metal plate, wherein the insulating film contains a thermosetting resin, and the thermosetting resin is a unit derived from terephthalic acid and isophthalic acid A polyester resin comprising a dicarboxylic acid-derived unit containing 90 mol% or more of the total derived units and a polyol-derived unit containing 90 mol% or more of a polyol-derived unit having 2 to 5 carbon atoms, the dicarboxylic acid-derived unit The molar percentage of the terephthalic acid-derived unit is 40 to 70%, the molar percentage of the isophthalic acid-derived unit in the dicarboxylic acid-derived unit is 30 to 60%, It is an insulating film laminated metal plate for forming a conductive thin film layer on the said insulating film whose adjusted average carbon number is 3.4 or less.

According to this structure, when forming a conductive thin film layer by sputtering on an insulating film, since softening resulting from the temperature rise of an insulating film is suppressed, the conductive thin film layer in which generation|occurrence|production of wrinkles was suppressed is formed. Furthermore, in the organic EL device fabricated using the insulating coating laminated metal plate of the present invention, the light emitting layer surface emits light uniformly.

In the insulating film-laminated metal sheet of the present invention, the insulating film may further contain a pigment. With this configuration, the organic EL device manufactured using the insulating coating laminated metal plate of the present invention reflects the light of the wavelength corresponding to the pigment in the insulating coating toward the device surface side, so that the luminance associated with the light of this wavelength is reduced. can be improved

It is preferable that the surface roughness in the area|region of the 3 mm square of the said insulation film laminated|multilayer metal plate of this invention is 10 nm or less. According to this structure, the surface of an insulating film becomes smooth in a practical range, and generation|occurrence|production of a dark spot can be suppressed. And by using the insulating film-laminated metal plate of this invention, a solar cell with high power generation efficiency and an organic EL element with high light emission illuminance can be produced.

Another aspect of the present invention is a metal substrate in which a conductive thin film layer is laminated on an insulating film of the insulating film-laminated metal plate.

According to this configuration, in the organic EL device produced using the metal substrate of the present invention, color non-uniformity and insufficient luminous intensity are less likely to occur. On the other hand, in the solar cell produced using the metal substrate of the present invention, power generation amount It becomes difficult to lower

The metal substrate of this invention WHEREIN: It is preferable that the surface roughness in the 3 mm square area|region of the said conductive thin film layer is 100 nm or less. According to this structure, the surface of a conductive thin film layer becomes smooth in a practical range, and organic electroluminescent element and solar cell with stable quality and lifetime can be produced.

The metal substrate of this invention can be used for a top emission type organic electroluminescent element or a substrate type thin film solar cell. According to this structure, a top emission type organic EL element with a stable light emission illuminance or a substrate type thin film solar cell with a stable power generation amount can be produced.

ADVANTAGE OF THE INVENTION According to this invention, the metal substrate with which generation|occurrence|production of the wrinkle on the surface of the conductive thin film layer was suppressed can be provided the insulating-film-laminated metal plate which can suppress the generation|occurrence|production of wrinkles at the time of formation of the conductive thin film layer by sputtering.

Example

Hereinafter, the present invention will be described in more detail by way of Examples. On the other hand, the present invention is not limited by the following examples, and it is possible to carry out the present invention by adding changes within the range suitable for the purpose of the preceding and the latter, and they are all included in the technical scope of the present invention.

[Production of polyester resin]

In an autoclave having a stirring device and a thermometer, the No. The raw material monomer of the polyester resin shown in 1 (input amount: 83.0 mass parts of terephthalic acid, 83.0 mass parts of isophthalic acid, 107.2 mass parts of ethylene glycol, 44.8 mass parts of neopentyl glycol) and 0.1 mass parts of antimony trioxide 180 under atmospheric pressure The condensation reaction proceeded by heating at -210°C for 180 minutes. Subsequently, while raising the temperature to 250°C, the pressure was reduced to 1 to 5 mmHg, and then the condensation reaction was further advanced for 180 minutes. Thereby, No. 1 polyester resin was obtained.

No. by NMR method. In the composition ratio of each structural unit of the polyester resin of 1, the molar percentage of the terephthalic acid-derived unit in the dicarboxylic acid-derived unit is 50%, the molar percentage of the isophthalic acid-derived unit in the dicarboxylic acid-derived unit is 50%, and the polyol-derived unit The molar percentage of ethylene glycol-derived units occupied was 80%, and the molar percentage of neopentyl glycol-derived units occupied in polyol-derived units was 20%.

Next, No. Among the production conditions of the polyester resin of No. 1, only the input amount of the raw material monomer was No. From the raw material monomer of the polyester resin of Table 1, No. By changing to the raw material monomers of the polyester resins shown in 2-9, respectively, No. Polyester resins of 2 to 9 were obtained, respectively. And, by NMR method, No. The composition ratio of each structural unit of the polyester resin of 2-9 was obtained. The results are shown in Table 1.

No. With respect to the polyester resins of 1 to 9, the average number of carbon atoms in the polyol-derived unit was calculated from the molar percentage of each derived unit in the polyol-derived unit obtained by the NMR method and the carbon number of each derived unit. Then, the adjusted average carbon number of the polyol-derived unit was calculated from the average carbon number of the polyol-derived unit and the molar percentage of the terephthalic acid-derived unit in the dicarboxylic acid-derived unit. Table 1 also shows these calculation results.

[Preparation of composition for insulating film production]

In a solvent in which equal amounts of xylene (boiling point: 140°C) and cyclohexanone (boiling point: 156°C) were mixed, No. 43.4 parts by mass of the polyester resin of 1 in terms of solid content, 14.5 parts by mass of melamine resin (Superbecamine (registered trademark) J-820-60 manufactured by DIC Corporation) in terms of solid content, titanium oxide particles (Taipeik manufactured by Ishihara Industrial Co., Ltd.) (registered trademark) CR-50 (average particle diameter 0.25 µm)) was added in terms of solid content in 16.0 parts by mass, and finally 0.3 parts by mass of triethylenediamine manufactured by Tokyo Chemical Industry Co., Ltd. was added, and No. The composition for insulating film preparation of 1 was obtained. On the other hand, the quantity of the mixed solvent of xylene and cyclohexanone was adjusted so that solid content of the sum total of a polyester resin and a melamine resin might be 58 mass %.

Next, No. Among the production conditions for the composition for preparing an insulating film of No. 1, only the polyester resin to be blended was selected as No. No. 1 from the polyester resin. By changing to each of the polyester resins of 2 to 9, No. Compositions for preparing an insulating film of 2 to 9 were obtained, respectively.

[Production of Insulation Coated Laminated Metal Sheet]

As the metal plate, using an electrically pure galvanized steel sheet having a sheet thickness of 0.8 mm and a zinc plating adhesion amount of 20 g/m ^{2 per each surface on both surfaces of the metal sheet, the No.} The composition for preparing an insulating film of 1 was applied with a bar coater so that the film thickness was set to 15 µm. And by baking and drying for 2 minutes so that the reached board temperature may be 220 degreeC, No. The insulating coating laminated metal plate of 1 was obtained.

Next, No. Among the production conditions for the insulating coating laminated metal sheet of 1, only the composition for preparing an insulating coating film to be applied was No. From the composition for preparing an insulating film of 1, No. By changing to each of the compositions for preparing an insulating film of 2 to 9, No. Insulation coating laminated metal plates 2 to 9 were obtained, respectively.

[Surface Polishing of Insulation Laminated Metal Sheet]

The holder to which the suction pad for mounting the substrate of the polishing apparatus was attached to the No. The insulating coating laminated metal plate of 1 was set, and it set on the polishing pad provided in the surface plate of a polishing apparatus with the insulation film facing down. As an abrasive, using alumina particles having a particle size of about 100 nm, pressure 65 gf/cm ² , rotation distance per 1 m, No. Chemical mechanical polishing was performed for 1 minute at each rotation speed of 50 rpm of the insulated-coated laminated metal plate of No. 1 and the surface plate.

Next, No. Under the same conditions as the surface polishing conditions of the insulating coating laminated metal sheet of 1, No. The surfaces of the insulating coating laminated metal sheets 2 to 9 were polished.

[Production of metal substrate]

The surface of the insulating film is chemical-mechanically polished No. The insulating coating laminated metal plate of 1 was washed in the following procedure. That is, No. The insulating coating laminated metal plate of 1 is first cleaned with ultrapure water, then ultrasonically cleaned with ultrapure water at 23 kHz for 3 minutes, then ultrasonically cleaned with a detergent for removing organic impurities at 23 kHz for 3 minutes, and then was washed with ultrapure water, then ultrasonically cleaned with an ionic impurity-removing detergent at 43 kHz for 3 minutes, then washed with ultrapure water, and then ultrasonically cleaned with ultrapure water at 1 MHz for 3 minutes, Next, isopropyl alcohol vapor washing was performed, and UV ozone washing was performed immediately before formation of the ITO layer. Then, by forming an ITO layer with a thickness of 100 nm on the insulating film under the sputtering condition of 300 W, No. A metal substrate of 1 was obtained.

Next, No. Among the manufacturing conditions of the metal substrate of No. 1, only the metal substrate was No. No. 1 from the metal substrate. By changing to each of the metal substrates of 2 to 9, No. Metal substrates 2 to 9 were obtained, respectively.

[judgment of the presence or absence of wrinkles]

No. For each of the metal substrates 1 to 9, the presence or absence of wrinkles was determined according to the following determination conditions using an atomic force microscope (AFM) (SPI3800N manufactured by Seiko Electronics Industries).

(Conditions for determining the presence or absence of wrinkles)

The surface of the ITO layer of the metal substrate was observed using an atomic force microscope, and convex groups of 20 to 50 μm in length, 5 to 10 μm in width, and 100 nm in height or more were observed in the area around 100 μm of the surface of the ITO layer. And the case where it was not observed is judged as wrinkle-free.

The determination result is shown in Table 1.

2, No. It is an atomic force microscope image of the surface of the ITO layer in the metal substrate of No. 1, and it shows that there is no wrinkle in the surface of an ITO layer. 3, No. It is an atomic force microscope image of the surface of the ITO layer in the metal substrate of 2, and shows that the ITO layer surface has wrinkles.

[Measurement of surface roughness in a 3 mm square area]

No. surface polished For each insulating film of the insulating film-laminated metal sheets 1 to 9, the surface roughness Ra' in a 3 mm square area was measured using the atomic force microscope described below in accordance with the following measurement method. Also, No. Also about the ITO layer of each metal substrate of 1-9, the surface roughness Ra' in the area|region of 3 mm square was measured using the said atomic force microscope.

(Measuring method of surface roughness in a 3 mm square area)

Using an atomic force microscope, based on the definition of arithmetic mean roughness stipulated in JIS B 0601 at four corners and at the center of a 3 mm square area, arithmetic mean roughness Ra1 in one direction in a 10 µm square area and the arithmetic mean roughness Ra2 in a direction perpendicular thereto. And let the average value of Ra1 and Ra2 be surface roughness Ra3 of the area|region of 10 micrometers square. And let the average value of surface roughness Ra3 of the said area|region of 10 micrometers square in said five places be surface roughness Ra' in the area|region of 3 mm square.

A measurement result is shown in Table 1.

[No. Evaluation of Insulation Coated Laminated Metal Plates and Metal Substrates 1 to 9]

No. 1, 5 to 7, the insulating coating laminated metal plate and metal substrate are examples which satisfy|fill each condition prescribed|regulated by this invention. These showed that there was no wrinkle in the ITO layer surface, and surface roughness Ra' in a 3 mm square area|region was 100 nm or less.

On the other hand, No. The insulating coating laminated metal sheet and the metal substrate of 2-4, 8, 9 are examples which do not satisfy|fill the conditions "the adjusted average carbon number of a polyol-derived unit is 3.4 or less" prescribed|regulated by this invention. These showed that the ITO layer surface had wrinkles, and surface roughness Ra' in a 3 mm square area|region exceeded 100 nm.

This application is based on Japanese Patent Application No. 2017-068818 for which it applied on March 30, 2017, The content is taken in here.

In order to express this invention, although this invention was suitably and fully demonstrated through embodiment in the above, it should be recognized by those skilled in the art that it is easy to change and/or improve the above-mentioned embodiment. Therefore, unless the modified form or improved form implemented by a person skilled in the art is at a level that deviates from the scope of the claims described in the claims, it is construed that the modified form or the improved form is encompassed by the scope of the claims. .

Claims (6)

It has a metal plate and the insulating film laminated|stacked on at least one surface side of the said metal plate,
The insulating film contains a thermosetting resin,
The thermosetting resin is a dicarboxylic acid-derived unit containing 90 mol% or more of terephthalic acid-derived units and isophthalic acid-derived units in total, and polyol-derived units containing 90 mol% or more of polyol-derived units having 2 to 5 carbon atoms. containing an ester resin,
The molar percentage of the terephthalic acid-derived unit in the dicarboxylic acid-derived unit is 40 to 70%,
The molar percentage of the isophthalic acid-derived unit in the dicarboxylic acid-derived unit is 30 to 60%,
The insulating film laminated metal plate for forming a conductive thin film layer on the said insulating film whose adjusted average carbon number of the polyol-derived unit computed by following formula (1) is 3.4 or less.
[Equation 1]

The method of claim 1,
The insulating coating layer further contains a pigment. The method of claim 1,
The insulating film-laminated metal sheet having a surface roughness of 10 nm or less in a 3 mm square region of the insulating film. The metal substrate in which the conductive thin film layer was laminated|stacked on the insulating film which the insulating-film-laminated metal plate in any one of Claims 1-3 has. 5. The method of claim 4,
The metal substrate whose surface roughness in the 3 mm square area|region of the said conductive thin film layer is 100 nm or less. 5. The method of claim 4,
The metal substrate used for a top emission type organic electroluminescent element or a substrate type thin film solar cell.

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